Mufid Elfgeeh, 32, had pleaded guilty in December in federal court in Rochester to attempting to provide material support to a terrorist organization in 2013 and 2014.
A naturalized U.S. citizen born in Yemen, Elfgeeh was operating a convenience store and pizzeria in Rochester when he was arrested by the Joint Terrorism Task Force in May 2014.
Investigators said he had bought two handguns and silencers that he planned to use to kill returning U.S.
Authorities said he also tried to recruit three people to join the Islamic State group to fight in Syria.
"Thanks to today's sentence, one of the first ISIL recruiters ever captured has been brought to justice and will now serve a very long jail sentence," said U.S. Attorney William Hochul. "But while this case strikes a significant blow against ISIL killers and wannabes, our ongoing efforts to eradicate terrorist groups will continue until all are brought to justice."
"I watched ISIS carry out acts of violence, such as beheadings and burning people alive," Elfgeeh said. "They say they do this for religion, I believe they are wrong."
He also discussed his motivation.
"Like many, I was interested in the Arab Spring in Tunisia, and how it spread through Africa and the Middle East," Elfgeeh said. "I wanted to help my Muslim brothers fighting the horrors of the Assad regime. I was an early supporter of ISIS, as they were the first to address the crisis in Syria."
His sentence includes more than 27 years of supervision after his release, including monitoring all of his Internet activity. Assistant U.S. Attorney Brett Harvey said that was because of Elfgeeh's active social media use during his plot.
Elfgeeh was accused of creating 23 Facebook pages, under various aliases, in order to contact ISIL members and recruit, as well as a WhatsApp account to arrange a contact for two people, referred to as "individuals A and B," to travel to Syria.
"The defendant showed use of social media, through various aliases, to support ISIL and help encourage other members," Harvey said. "The defendant worked to send three people to Syria to fight with ISIL, and though he did not fight on the ground, he considered himself a fighter to help form the Islamic State and impose Shariah Law."
U.S. District Judge Elizabeth Halford sentenced Elfgeeh after saying, "Political beliefs are all fine and good, but you went far beyond. You were sending money, and since you had limited resources, while it's not a significant amount, it shows how dedicated you were to this cause."
The judge also said she believed Elfgeeh has mental health issues that have gone untreated.
In his statement, Elfgeeh offered insight into his background.
"I came to America with my father at the age of 13, and when he returned to Yemen when I was 14 and I was left alone in New York City," Elfgeeh said. "I couldn't go to school, partly because I didn't know the language and partly because I always had to work to support myself.
"I became isolated, I began drinking and using marijuana," he said. "I traveled around the country working at convenience stores, but I had no one, no door that I could knock on."